Todour is an application for handling todo.txt files (as made famous by Gina Trapani of Lifehacker) on the mac and windows.
There is no support for anything fancy like dates, but you can add, remove, search, mark done, mark undone and archive. That's it, and that's probably all there is ever going to be. The application always works directly on the todo.txt and done.txt files when any action is performed. There is no caching or intermediate storage of any kind or need to save. The application should be mostly self explanatory otherwise and I hope it is of some value to you using it.